JPH0963542A - High pressure discharge lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stop generation of pulse voltages when a high pressure discharge lamp is not started to operate by some reasons. SOLUTION: A series circuit of a starter 2 and a heat-reacting switch 3 is connected in parallel with an emission tube 1, the starter 2 comprising a glow starter 7 and a resistance heating element 8. When the emission tube 1 is not started to operate, the resistance heating element 8 generates heat, by means of which the glow starter 7 is closed to eliminate sharp changes in current that keeps flowing through a ballast 10, so as to stop generation of pulse voltages.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high pressure discharge lamp.

[0002]

2. Description of the Related Art Conventionally, in a high-pressure discharge lamp such as a high-pressure sodium lamp, a starting rare gas such as xenon gas is sealed in the arc tube and the sealing pressure is increased to improve the efficiency. Since the high-voltage discharge lamp has a high starting voltage, a starter 14 composed of a series circuit of a bimetal switch 12 and a heating resistor 13 is connected in parallel with the arc tube 1 as shown in FIG. It is housed inside. The starter 14 heats the bimetal switch 12 by heating the heating resistor 13 red, and when the bimetal switch 12 is opened, the current flowing in the ballast 10 is rapidly cut off to generate a pulse voltage.

[0003]

In the above-mentioned conventional high-pressure discharge lamp, when the starting voltage of the arc tube remarkably rises at the end of the life of the discharge lamp or due to some reason such as a mechanical shock from the outside, the arc tube is exposed to light. When the connection is broken, the arc tube does not start, the power supply voltage continues to be applied to the starting unit, and the pulse voltage continues to be generated. If the power switch is left on in such a state, there is a possibility that the life of the ballast may be shortened due to the continuous application of the pulse voltage, or the insulation of the wiring between the ballast and the lamp may be deteriorated.

The present invention has been made in order to solve the above-mentioned problems of the prior art, and provides a highly safe high-pressure discharge lamp which does not generate a pulse voltage when the arc tube does not start for some reason. Is intended.

[0005]

In order to achieve the above object, the high-pressure discharge lamp of the present invention comprises a glow starter, a resistance heating element, and a series circuit including a normally-closed heat-responsive switch connected in parallel to an arc tube. When the arc tube is housed in the outer tube and the arc tube does not operate, the contact of the glow starter is closed by the heat of the resistance heating element, and the thermal response switch is also closed, and the switching temperature of the thermal response switch. Is 100-
The glow starter is installed at a position within a range of 350 ° C. and a temperature of 150 ° C. or higher due to heat from the resistance heating element. In the above structure, the resistance heating element is preferably a ceramic heater. Further, in the above configuration, the cold resistance value of the resistance heating element is 100Ω.
It is preferably ˜500 Ω. Further, in the above configuration, it is preferable that the glow starter is arranged between the resistance heating element and the heat responsive switch.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A high pressure discharge lamp of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing the circuit configuration of the high pressure discharge lamp of the first embodiment, and FIG. 2 is a front view showing the configuration of the main parts of the high pressure discharge lamp.

As shown in FIG. 1, in the high pressure discharge lamp of the present invention, a series circuit composed of a starter 2 and a heat-responsive switch 3 is connected in parallel between both electrodes 1a and 1b of the arc tube 1, It is stored in the outer tube 4. When the high pressure discharge lamp is a high pressure sodium lamp, the inside of the outer tube 4 is generally maintained in a high vacuum. On the other hand, when the high pressure discharge lamp is a metal halide lamp, the outer tube 4 may be filled with an inert gas such as nitrogen. One electrode 1a of the arc tube 1 is connected to a starting auxiliary conductor 5 via a starting auxiliary thermal responsive switch 6. The starting auxiliary conductor 5 is wound along the outer surface of the arc tube 1 and is provided close to the arc tube 1. Both electrodes 1a and 1b of the arc tube 1 are connected to a power source 11 via a ballast 10.

The starter 2 comprises a series circuit of a glow starter 7 and a resistance heating element 8 for limiting the current flowing through the glow starter 7. The thermal response switch 3 stops the supply of current to the starter 2 after the discharge of the arc tube 1 is started. The recovery time of the thermal response switch 3 is longer than the recovery time of the startup assistance thermal response switch 6 in order to ensure lighting when the lamp is restarted, that is, when the current to the lamp is cut off and then turned on again. Is set to. The arrangement of the starter 2 and the thermal switch 3 is shown in FIG. As shown in FIG. 2, the glow starter 7 comes into contact with the resistance heating element 8, and the heat-responsive switch 3 is arranged above the glow starter 7 so that it is less likely to receive heat from the resistance heating element 8.

Next, FIG. 3 shows an example of the structure when the arc tube 1 having an auxiliary electrode is used. The configuration example shown in FIG. 1 is different from that of FIG. 1 in that the starting auxiliary conductor 5 and the starting auxiliary thermal responsive switch 6 are not provided, and that the resistor 9 for suppressing the current to the auxiliary electrode is the electrode 1b of the arc tube 1. And the point provided between the starter 2 and the connection point of the thermal response switch 3 are different.

Next, the high pressure sodium lamp of the present invention is
The operation when the ballast 10 and the power source 11 having an inductive property are used for lighting will be described. First, when a power supply voltage is applied to the high-pressure sodium lamp having any of the above configurations via the ballast 10, a current flows in the starter 2. When the glow starter 7 of the starter 2 performs an opening / closing operation, a rapid change in the current flowing in the ballast 10 occurs and a pulse voltage is induced in the ballast 10. Then, the discharge of the arc tube 1 is started due to the pulse voltage and the start auxiliary effect of the start auxiliary conductor 5 provided on the outer surface of the arc tube 1. After the start of discharge, the heat-responsive switch 6 for starting assistance and the heat-responsive switch 3 are opened by the heat from the arc tube 1,
The voltage application to the starting auxiliary conductor 5 and the starter 2 is stopped.

In a state where the arc tube 1 operates normally, the time from the application of the power supply voltage to the start of the discharge of the arc tube 1 is at most several seconds, and the resistance heating element 8 during this period. The glow starter 7 does not reach the closed circuit temperature even if it is heated by. However, at the end of the life of the lamp, the starting voltage of the arc tube 1 remarkably rises, and due to a mechanical shock from the outside, a part of the current supply line to the arc tube 1 is cut off. When it becomes impossible to start, the arc tube 1 does not start discharging even if the power supply voltage is applied, and the glow starter 7 continues the opening / closing operation.
Current continues to flow intermittently in the circuit of the starter 2, and the temperature of the resistance heating element 8 rises. As a result, the glow starter 7 is heated. When the temperature of the glow starter exceeds the closing temperature of the contacts attached to the glow starter 7, the glow starter 7 is always closed. Therefore, there is no sudden change in the current, and the generation of the pulse voltage by the ballast 10 is stopped.

[0012]

Next, specific examples of the present invention will be described. The circuit configuration shown in FIG. 1 is arranged as shown in FIG.
A 0 W high pressure sodium lamp was created. The arc tube 1 has an outer diameter of 9 mm and a distance between electrodes of 58 mm. The closing temperature of the contacts of the glow starter 7 is about 100 ° C, and the heat resistant temperature of the valve is about 550 ° C. As the resistance heating element 8 connected in series to the glow starter 7, a square ceramic heater having one side of 30 mm was used. The resistance value of the ceramic heater at room temperature was about 100Ω, and the resistance value at a saturation temperature of about 500 ° C was about 500Ω. A bimetal switch having an open circuit temperature of about 200 ° C. was used as the thermal response switch 3 connected in series to the starter 2 composed of these components.

Here, the cold resistance value of the resistance heating element 8 is set to about 10
Although it was set to 0Ω, if the cold resistance value is 100Ω or less, the current flowing through the starter 2 is large, so the glow starter 7
Will deteriorate very quickly. On the other hand, in the case of 500Ω or more,
Since the current flowing through the starter 2 is small, a sufficient pulse voltage for starting the arc tube 1 cannot be obtained. for that reason,
Practically, the range of about 100 to 500Ω is suitable.

Further, although the open circuit temperature of the thermal responsive switch 3 is set to about 200 ° C., the ambient temperature when the lamp is actually used is at most about 50 ° C., and in this case, the thermal responsive switch 3 is reliable. Need to be closed.
Further, the heat responsive switch 3 must be arranged so as not to interfere with light emission when the lamp is lit. Further, since the current supply to the starter 2 is stopped when the lamp is turned on, it is necessary to surely open the thermal response switch 3.
Taking these into consideration, practically about 100 to 350 ° C
It is enough if it is within the range of.

By widening the contact interval of the glow starter 7, the operating temperature of the contact can be raised and a high pulse voltage can be obtained. However, along with that, the operating voltage of the glow starter 7 rises and the performance thereof deteriorates. Therefore, the operating temperature of the contact is practically optimal at about 10
It is 0 ° C. In order to surely close this contact, the glow starter 7 may be installed at a position where the temperature becomes 150 ° C. or higher.

The high-pressure sodium lamp manufactured according to the above specifications was connected to an AC power source of 200 V through a ballast for high-pressure mercury lamp of 250 W, and light was emitted within a few seconds after the power was turned on through the process described above. The tube 1 started normally and transitioned to a stable lighting state. Next, in order to perform an experiment in a state where the arc tube 1 cannot be started, after the lamp is turned off and cooled, a laser beam is used to destroy the outer tube 4 without destroying the outer tube 4. The current supply line to No. 1 was disconnected, and the arc tube 1 was put into a state in which it could not be started. When the power supply voltage was applied in this state, the current continued to flow in the starter 2 and the temperature of the ceramic heater rapidly increased, and after about 30 seconds, the contact of the glow starter 7 was closed and the generation of the pulse voltage was stopped. That is, it was confirmed that the high-pressure discharge lamp of the present invention operates for the intended purpose.

[0017]

As described above, according to the present invention,
In the outer tube, in addition to the arc tube, a series body including a glow starter, a resistance heating element, and a normally-closed heat-actuated switch was connected in parallel with the arc tube and housed. Even if the arc tube becomes unstartable due to an accident, such as the voltage rising significantly or a part of the current supply line to the arc tube being cut due to external mechanical shock, the heat of the resistance heating element Causes the glow starter to close,
Moreover, since the thermal switch is also closed, the sudden change in current disappears and the generation of pulse voltage by the ballast stops. As a result, it is possible to prevent the insulation of the ballast and the lighting circuit wiring from being lowered, and a high-safety high-pressure discharge lamp can be obtained.

The glow starter is closed by setting the switching temperature of the heat-responsive switch within the range of 100 to 350 ° C. and installing the glow starter at a position where the temperature from the resistance heating element becomes 150 ° C. or higher. At this time, the heat responsive switch can be surely closed. Also,
Since the electric current supply to the starter is stopped when the lamp is turned on, the thermal response switch can be surely opened.

Further, when the resistance heating element is a ceramic heater, a resistance value of about 100Ω at room temperature and a resistance value of about 500Ω at a saturation temperature of about 500 ° C. can be obtained. In addition, the resistance heating element can be downsized and does not interfere with light emission when the lamp is turned on. In addition, the cold resistance value of the resistance heating element is set to 10
By setting it in the range of 0 to 500Ω, a pulse voltage sufficient to start the arc tube can be obtained and the glow starter is not rapidly deteriorated. Furthermore, by disposing the glow starter between the resistance heating element and the heat-responsive switch, the glow starter blocks heat from the resistance heating element, so that the heat-responsive switch is less likely to receive heat,
Can maintain a normally closed state.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a circuit configuration of an embodiment of a high pressure discharge lamp of the present invention.

FIG. 2 is a front view showing the arrangement of essential parts in one embodiment of the high-pressure discharge lamp of the present invention.

FIG. 3 is a schematic diagram showing a circuit configuration of another embodiment of the high pressure discharge lamp of the present invention.

FIG. 4 is a schematic diagram showing a circuit configuration of a conventional high pressure discharge lamp.

[Explanation of symbols]

 1: Arc tube 2: Starter 3: Thermal response switch 4: Outer tube 5: Starting assistance conductor 6: Starting assistance thermal response switch 7: Glow starter 8: Resistance heating element 9: Resistor 10: Ballast 11: Power supply 12: Bimetal switch 13: Heating resistor 14: Starter

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hong Gion 1-1, Saiwaicho, Takatsuki City, Osaka Prefecture Matsushita Electronics Industrial Co., Ltd.

Claims (4)

[Claims] A series circuit including a glow starter, a resistance heating element and a normally closed thermo-responsive switch is connected in parallel to an arc tube and housed inside an outer tube, and when the arc tube is inoperative, the resistance heating is performed. A high-pressure discharge lamp in which the contact of the glow starter is closed by the heat of the body and the thermal response switch is also closed, and the switching temperature of the thermal response switch is in the range of 100 to 350 ° C. A high pressure discharge lamp in which the glow starter is installed at a position where the temperature is 150 ° C. or higher due to heat from a heating element. 2. The high pressure discharge lamp according to claim 1, wherein the resistance heating element is a ceramic heater. 3. The cold resistance value of the resistance heating element is 100Ω to
The high pressure discharge lamp according to claim 1 or 2 having a resistance of 500Ω. 4. The high pressure discharge lamp according to claim 1, wherein the glow starter is located between the resistance heating element and the heat responsive switch and is remote.